Push-pull switch



Nov. 22, 1949 D. w. JOHNSON 2,489,185

PUSH-PULL SWITCH Filed Feb. 6, 1945 2 Sheets-Sheet 1 10. III,

1N VEN TOR.

/52 a y;'- 5 DA wb 14 JOHNSON BY HIS ATTORNEYS Patented Nov. 22, 1949PUSH-PULL SWITCH David W. Johnson, New Britain, Conn., assignor to TheArrow-Hart & Hegeman Electric Company, Hartford, Conn., a corporation ofConnecticut Application February 6, 1945, Serial No. 576,419

This invention relates to push-pull electric switches wherein the switchparts normally occupy a central position, from which they can be movedby pulling a handle to establish certain circuits or by pushing thehandle to establish other circuits.

It is an object of this invention to provide an improved electricpush-pull switch mechanism of the foregoing type having ruggedconstruction to stand continuous hard use, while at the same timepossessing the characteristic of ease of operation.

Another object of the invention is to provide a push-pull switchstructure which, when in its central position, will maintain one or moresets of contacts in engagement and which, when pushed or pulled, willmaintain the engagement of one of said sets and will at the same timeestablish a new circuit or cause engagement of another set of contacts.

Another object of the invention is to provide a push-pull switch of theforegoing type utilizing a contact carrying member that is normally heldin equilibrium in a central position by opposing spring actions, butwhich may be tilted upon pushing or pulling of the switch handle toaccomplish a variation in contact engagements including the maintenanceof one previously existing contact engagement.

Other objects and advantages will become apparent to those skilled inthe art as the invention is described in connection with theaccompanying drawings.

In the drawings- Fig. 1 is a side elevation view partly broken away of aswitch embodying the invention.

Fig. 2 is an elevational view, from the opposite side, of the switchillustrated in Fig. 1.

Fig. 3 is an end elevation view of the switch of Fig. 1.

Fig. 4 is a bottom view of the switch of Fig. 1.

Fig. 5 is a section view taken along line 5-5 of Fig. 4, illustratingthe parts in central position.

Fig. 6 is a section view similar to Fig. 5 with the parts in pushedposition.

Fig. 7 is a section view similar to Fig. 5 with the parts in pulledposition, and

Fig. 8 is a detailed plan view of the contact carrier and the bridgingcontacts.

Referring to the drawings, the parts are 8 Claims. (Cl. 200-16) mountedwithin a molded insulated base or body [0 which is provided, during themolding operation, with the necessary recesses, apertures and ledges forthe reception of the fixed and movable switch parts (as will hereinafterbe described).

A handle 12, preferably molded of insulating material into the formillustrated in Figs. 1-3, may be pushed or grasped and pulled to opcratethe movable switch parts. The handle is mounted upon a metallic spindleor shaft Id preferably during the molding of said handle. The lower orinner portion of said handle is preferably cylindrical and receivedwithin a circular wellor recess I6 formed in the top surface of the baseIt and the spindle extends through a smaller circular passage I8 in thebottom of the well 15. Three shoulders at, b, and c (Fig. 5) are formedon the shaft by providing the shaft with several portions ofprogressively reduced diameters.

Against the shoulder a of shaft I4 is pressed a circular washer 29 by acoiled compression spring 22 whose opposite end presses upon a flange 24radially extending from a sleeve member 26 which is slidably mountedupon the central portion of the shaft 14. The sleeve member 26 extendsthrough an aperture 39a in an insulating contact carrier 30 which may bestamped from sheet insulation in the form illustrated in Fig. 8. As thespring 22 tends to expand, it presses the flange 2d of the sleeve 25against the innermost surface of the contact carrier 3i]. This urge isresisted by a cup-shaped member 32 located on the opposite side of thecontact carrier 3t and slidably mounted upon the lower portion of theshaft I l. For passage of shaft [4, the bottom of the cup 32 isapertured, and its inner peripheral Walls are of diameter to slidablyreceive the lower end of the sleeve member 26. A circular peripheralflange 32a is preferably provided on the top portion of the cup memberto provide sufficient bearing area against the lower face of the contactcarrier 30. The cup member 32 is urged against the face of the contactcarrier 30 by the upper end of a compression spring 36 coiled aroundshaft M. The lower end of the spring rests upon the flange of a smallsleeve or spring retainer which is slidably mounted upon the lower endof the shaft I4 and seats upon the stamped sheet metal guide member ll]having wings 40a extending in diametrically opposite directions andsliding within longitudinal recesses 42 molded in the walls of a centralpassage 44 in the bottom of base II). The guide member 40 may be heldupon the lower end of the shaft by any suitable means such as a screw itor by peening over the lower end of the shaft against a Washer 41 on aneck at the shaft end.

Two pairs of upper and lower fixed contact and terminal members aremounted on each of two opposite sides of the switch base. Since thepairs of upper and lower terminal and contact members are alike on oneside, description of one pair will suffice. The lower set on one sidecomprises contact and terminal members (designated generally by numerals50 and 52) stamped from sheet metal into the form illustrated in Fig. 1.A terminal portion lite is bent at right angles to an anchor portionBill); and offset downwardly from the anchor portion is a contactportion 500 which has a contact button 53d riveted on its inner or uppersurface. The anchor portion 50b is secured by means of a hollow rivet 56against the bottom surface of a projection 56 molded integrally with thebase ID. A flanged insulating washer 58 insulates the shank and head ofthe rivet from the terminal member. Such rivets also serve to secure theupper set or pair of contact members (designated generally by numerals50 and 62) against the upper surface of the projections 54. These uppercontact members are stamped from sheet metal with the terminal portion,62a for example, resting upon the upper surface of the projection 54.Contact supporting portion 62b is ofiset downwardly and has contactbutton 62d on its lower surface. For bridging the contact buttons of theupper contact members 50 and 62 when the contact carrier it is incentral position, a bridging contact I is provided; and for bridging thecontact buttons of the lower contact members 50 and '52, when the handleI2 is pressed down, a bridging contact member I2 is provided. Thebridging contacts Ill and I2 are located opposite each other on theupper and lower surfaces respectively at one end of the contact carrier30 and are riveted thereon.

At the opposite end of the contact carrier are mounted upper and lowerbridging contact members I10, H2 in similar manner and of similarstructure to the bridging contacts I0 and "I2. These bridging contactsITO and I112 engage with upper and lower sets of fixed contacts I60, I62and I50, I52 respectively, which are similar in structure to thecontacts 50, 52 and B0, 62, except that the button carrying portions ofthese contacts are offset upwardly instead of downwardly so that incentral position of the contact carrier 30, when the upper bridgingcontact I0 engages with the upper stationary contacts 60, 62, the lowerbridging contact In will engage with the lower stationary contacts I50,I52.

By referring to Figures 5, 6, 7, it may be observed that upon pushing ofthe handle I2, the shaft I4 descends. This causes the shoulder a on theshaft to move the washer 20 downwardly and compresses the upper spring22 causing the contact carrier 3|] to tilt downwardly into the positionof Figure 6. The contact carrier is caused to tilt from the position ofFigure 5 to the position of Figure 6 because the bridging contact Hz wasengaged and remains engaged with the lower fixed contacts I55, I52. Thetilting of the contact carrier also causes the bridging contact "I0 todisengage the upper fixed contacts 60 and 82, and the bridging contactI2 to engage the lower fixed contacts 50 and Upon release of the handleii, the Spring returns the parts to the position in Figure 5. During thedownward motion of the shaft i i, no substantial action of the lowerspring 35 takes place for the reason that the intermediate shoulder 22on the shaft I4 carries the spring and its upper and lower retainers 32and 38 downwardly with the shaft as a unit.

Continued pushing on the handle I2, after the contact carrier hasassumed the position in Figure 6, results in no harmful effect becausecontinued downward movement or over-travel is permitted before the upperspring 22 becomes fully compressed.

When the handle I2 is pulled, the shaft I4 ascends. This ascent causesthe upward movement of the lower spring retainer 38 with the shaft tocompress the lower spring 36. The pres sure of the spring 35 istransmitted to the upper spring retainer and by that member to thecontact carrier til causing the carrier to tilt from the position inFigure 5 to the position in Figure 7. The contact carrier is caused totilt because the bridging contact lb was engaged and remains engagedwith the upper fixed contacts ill] and 62 during the pulling action. Thetilting of the contact carrier also causes bridging member I12 todisengage the lower fixed contacts I50, I52 and bridging contact I'lt toengage the upper fixed contacts Hill and H52. During this movement, theupper spring "22 can expand upwardly to some extent by reason of theraising of the Washer 20 and shaft I i and the accompanying smaller riseof the sleeve Continued upward pull of the handle I2 after the contactcarrier has assumed the position in Figure '7 results in no harmfuleffect, lost motion and over travel is permitted before the spring 3i)becomes fully compressed.

From the foregoing it may readily be understood that the inventionprovides for maintaining the lower set of contacts engaged at one sideof the switch when the handle is pushed to cause disengagement of theupper set at the opposite side of the switch and engagement of the lowerset on that opposite side. In like manner, the invention provides formaintaining the upper set of contacts engaged on the opposite side whenthe handle is pulled to disengage the lower set on the first mentionedside and engage the upper set on that side. Furthermore, the means foraccomplishing the aforementioned functions and actions is entirelynovel; also the switch is of sturdy construction and its individualparts may be inexpensively manufactured from readily available materialsby common manufacturing processes.

Many modifications within the scope of my invention will be apparent tothose skilled in the art. Therefore, I do not limit my invention to theembodiment shown or described.

What I claim is:

1. An electric switch comprising a shaft mova ble back and forward froma central position, a pair of oppositely acting springs mounted on andmovable with said shaft, a tiltable contact carrier movable by saidshaft, contact means mounted on said carrier, a plurality of fixedcontact means engagcable by said contact means, said springs acting onsaid shaft and carrier to hold said shaft and carrier at rest in thecentral position and means causing said contact means to establishengagement of certain of said fixed contact means and disengagement ofcertain other of said fixed contact means as said carrier is tilted fromcentral position while maintaining the pre-existing condition of otherof said contact means.

2. An electric switch comprising a shaft movable back and forward from acentral position, a tiltable contact carrier movable by said shaft,contact means mounted on said carrier, a plurality of fixed contactmeans engageable by said contact means, spring means mounted on saidshaft acting oppositely on said carrier to hold said carrier and shaftat rest in a central position and also causing said contact means toestablish engagement of certain of said fixed contact means anddisengagement of certain other of said fixed contact means as saidcarrier is tilted in one direction from central position, whilemaintaining the pre-existing condition of other of said contact means.

3. In an electric switch, a movable contact carrier having contactsurfaces at both ends and on opposite faces, springs mounted on saidshaft acting oppositely on said carrier to hold it in a central positionnormally, fixed contact means engaged by the contact surface which is atone end and on one face of the carrier when the carrier is in centralposition, other fixed contact means engaged by the contact surface whichis at the other end and on the opposite face of the carrier when thecarrier is in central position, a third fixed contact means engageableby the contact surface on the opposite face of said one end of thecarrier when the carrier is moved in one direction. while the conditionof contact engagement at the opposite end is maintained, and a fourthfixed contact means engageable by the contact surface which is on thereverse face of said other end when said carrier is moved in the otherdirection from central position while the condition of contactengagement at said one end is maintained.

4. In an electric switch, a shaft, a contact carrier mounted on saidshaft and movable from a central position in opposite directions,springs mounted on said shaft acting oppositely on said carrier tomaintain said carrier normally in central position, means on said shaftanchoring opposite ends of said springs, upper and lower contactsurfaces at the ends of said carrier, fixed contact means engaged bysaid upper contact surface at one end of the carrier and other fixedcontact means engaged by the lower contact surface at the other end ofthe carrier in the central position of the carrier, third fixed contactmeans engageable by the lower contact surface on said one end of thecarrier when said carrier moves downwardly while contact conditions atthe opposite end of the carrier are maintained, and a fourth fixedcontact means engageable by the upper contact surface at said oppositeend of the carrier when said carrier moves upwardly from centralposition while contact conditions at said one end of the carrier aremaintained.

5. In a push-pull switch, an axially movable shaft, a contact carriermovably mounted on said shaft, fixed members located on opposite sidesof said shaft, plural spring means mounted on said shaft holding saidcarrier with a surface at one end normally in engagement with one ofsaid fixed members and with an opposite surface at the other end inengagement with another of said fixed members, means on said shaftlimiting expansion of one of said springs, means on said shaft limitingexpansion of a second of said springs in one direction, expansion ofsaid second spring in the opposite direction being opposed by the firstspring whereby on movement of said shaft from normal position thecarrier will tilt about one or the other of said fixed members anddisengage the other.

6. In an electric switch, a shaft, contact carrying means mounted onsaid shaft, fixed members located adjacent opposite ends of saidcarrying means, means mounted on and moving with said shaft andresiliently holding said carrying means with a surface at one endnormally in engagement with one of said fixed members and an oppositelyfacing surface at the other end in engagement with another of said fixedmembers, and means to move said carrying means from said normal positionby causing tilting about one or the other of said fixed members andconcomitant disengagement of the fixed member which is opposite the tiltpoint.

7. An electric switch, as set forth claim 6, having contact surfaces ateach end of said contact carrying means, said fixed members being switchcontacts whereby tilting of said carrying means results in maintainingengagement of one set of contacts while another set becomes disengaged.

8. An electric switch, as set forth in claim 6, having contact surfacesat each end of said contact carrying means, fixed contacts includingsaid fixed members above and below each end of the carrying means,whereby tilting of said carrying means results in maintaining engagementof contacts at one end of the carrying means and disengagement of onecontact and engagement of another contact at the other end of thecarrying means.

DAVID W. JOHNSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,004,005 Ferguson Sept. 26, 19111,689,075 Lehman Oct. 23, 1928 1,925,585 Friedman Sept. 5, 19332,190,299 Van Valkenburg Feb. 13, 1940 2,203,297 Granberg June 4, 19402,254,768 Bierenfeld Sept. 2, 1941 2,335,283 Johnson Nov. 30, 19432,381,075 Nelsen Aug. 7, 1945 2,423,387 Johnson July 1, 1947

